1. Field of the Invention
The present invention relates to an autonomous robot ball capable of displacing in various environments, including indoors as well as outdoors.
2. Brief Description of the Prior Art
Upon designing a robot, the main difficulty is to make it sufficiently robust to sustain all environmental and operating conditions: shocks, stairs, carpets, various obstacles, manipulations by the children in the case of a toy, etc.
Prior art wheeled robot can turn upside down and, then, be incapable of relieving this deadlock.
A prior art solution to this problem is to use wheels bigger than the body of the robot. However, this does not prevent the robot from blocking in elevated position onto an object.
Another solution to this problem is described in the following prior art patents:
U.S. 3,798,835 (McKeehan) Mar. 26, 1974 PA1 U.S. 5,533,920 (Arad et al.) Jul. 9, 1996 PA1 U.S. 5,947,793 (Yamakawa) Sep. 7, 1999 PA1 CA 2 091 218 (Christen) Jul. 5, 1994 PA1 the encapsulating shell comprises a generally spherical outer face; PA1 the annular tread surface is generally elliptical in a cross sectional plane in which the axis of rotation is lying; PA1 the pivot axis is substantially perpendicular to the axis of rotation; PA1 the stator portion comprises a platform; PA1 the first motorized mechanism comprises at least one electric drive motor having a stator and a rotor, the stator of the electric motor is secured to the platform, the rotor of the electric motor is centered on the axis of rotation and is connected the shell; PA1 the first motorized mechanism comprises first and second electric drive motors each having a stator and a rotor, the stator of the first electric drive motor is secured to the platform, the stator of the second electric drive motor is secured to the platform, the rotor of the first electric drive motor is centered on the axis of rotation and is connected a first point of the shell, and the rotor of the second electric drive motor is centered on the axis of rotation and is connected to a second point of the shell diametrically opposite to the first point of this shell; PA1 the platform comprises an underside, the second motorized mechanism comprises an electric servomotor having a stator and a rotor, the stator of the electric servomotor is secured to the underside of the platform, and the rotor of the electric servomotor is centered on the pivot axis and is connected to the counterweight; PA1 the counterweight comprises an electric battery; PA1 the counterweight comprises an electric battery and a bracket to mechanically connect the battery to the rotor of the servomotor; PA1 the robot ball further comprises an inclinometer so mounted on the platform as to measure an inclination of this platform about the pivot axis, and a controller of the electric servomotor in relation to the measured platform inclination about the pivot axis; and PA1 the robot ball further comprises at least one external sensors and a robot ball controller responsive to these sensors, these external sensors comprise a robot ball spin sensor unit detecting spinning of the robot ball, a voice instructions recognising system, and/or a tactile system, and the robot ball further comprises a voice message generating system controlled by the robot ball controller; PA1 the robot ball further comprises an obstacle detector and a controller of the second motorized mechanism in response to an obstacle detected by the obstacle detector.
This solution consists of building a robot around a spherical shell enclosing a drive system. This drive system comprises an electric drive motor for rotating the spherical shell about an axis of rotation and thereby propelling the robot. The counter-rotating force on the electric drive motor is produced by a counterweight spaced apart from the axis of rotation. A drawback of such prior art robot balls is that steering thereof is not provided for.